Java Interview Questions

Hashtable Hashtable is basically a datastructure to retain values of key-value pair. It didn’t allow null for both key and value. You will get NullPointerException if you add null value. It is synchronized. So it come with its cost. Only one thread can access in one time Hashtable<Interger,String>; cityTable=new Hashtable<Interger,String>(); cityTable.put(1,”Lahore”); cityTable.put(2,”Karachi”); cityTable.put(3,null); // NullPointerException [...]

you are reading my article because you want to learn how to write stored procedures. You are new to this, and you don’t know where to start. You are exactly where I was when I wanted to learn how to write stored procedures. The purpose of this article is to help the developer who doesn’t [...]

So far, we’ve focused on the mechanics of serializing an object. We’ve assumed we have a serializable object and discussed, from the point of view of client code, how to serialize it. The next step is discussing how to make a class serializable. There are four basic things you must do when you are making [...]

Serialization is a mechanism built into the core Java libraries for writing a graph of objects into a stream of data. This stream of data can then be programmatically manipulated, and a deep copy of the objects can be made by reversing the process. This reversal is often called deserialization. Note: When serializing an object [...]